Incandescent-electric-lamp tool.



E. F. DWYER.

INGANDESGENT ELECTRIC LAMP TOOL.

APPLICATION I ILED FEB. 21, 1908.

Patented Jan. 19. 1909.

UNITED STATES FATENT @FFTCE.

ELMER F. DWYER, OF LYNN, MASSACHUSETTS.

INGANDESCENT-ELECTRIG-LAMP TOOL.

Application filed. February 21, 1908.

To all whom it may concern:

citizen of the United States, residing at Lynn, in the county of Essex and Commonwealth of hiiassachusetts, have invented a new and useful Incandescent-Electric-Lamp Tool, of which the following description, in connection with the accompanying drawings, is a specification.

In the carbon filament incandescent electric lamp as made at the present time having a looped filament known as the oval anchor filament a short wire called an anchor wire projects from the inside part or stem of the lamp, and to this anchor wire the loop of the filament is attached. WVhen a lamp burns out the filament is useless, and in order to repair or renew the lamp the old filament is replaced by a new one. The work of removing the old filament and putting in the new filament is done through a hole made by breaking off the tip of the glass bulb of the lamp.

Those who are engaged in manufacturing new lamps or in repairing or renewing old lamps find it necessary in many cases to either shorten or lengthen the anchor wire to fit the particular filament that it is intended to use. They also find it desirable to have the hole in the bulb as small as possible because the difficulty in sealing increases with the size of the hole. A hole three-sixteenths of an inch in diameter can be closed without special difficulty, while a hole one-fourth of an inch in diameter requires special skill and considerably more time. Tools for repairing and renewing lamps have been made from comparatively large steel tubing with a sufiicient thickness of wall to form the necessary cutting edge; also from a comparatively small steel or brass tube with projecting jaws, but which make the total diameter so great that a comparatively large hole in the bulb is necessary for its insertion. The tool that I am about to describe can be inserted through a threesixteenths of an inch hole, and used to shorten the anchor wire by cutting. It may also be used as a pair of pliers for holding the filament or any other part or for pinching anypa-rt without cutting in any operation inside the lamp bulb. I am enabled to obtain the extremely small diameter mentioned without afiecting the capacity of the tool by a peculiarity of construction which I will proceed to describe.

Specification of Letters Patent.

I Be it known that I, ELMER F. DWYER, a

Patented Jan. 19, 1969.

Serial No. 7,265.

While I use a hollow steel shaft and use the wall of thisshaft as one of the cutting edges, I am not limited to the thickness of the wall of a symmetrical tube for the length of the cutting edge because by making an eccentric bore in the shaft the wall of the shaft can be made as thick on one side as will leave steel enough on the other side to retain the inner shaft, and this wall may be as thin as one-siXty-fourth of an inch, and by using an inner shaft three-thirty-seconds of an inch in diameter ample stock is left for forming the cutting edge. It is evident that the inner shaft must be of such a diameter as to withstand the tendency to twist when the operating power is applied at the lever or handles, and the dimension stated is found to be sufficient for that purpose. It is also evident that the shafts must be of sufiicient length to reach from outside the hole in the bulb to the inside part or stem of the lamp, which is usually less than four inches.

The tool consists of a steel shaft bored eccentrically from end to end as stated above, with a cutting edge on one end, the cutting edge being on the part of the circumference farthest from the bore; a steel shaft which fits into the bore in the outer shaft and which has an enlarged head with a diameter not greater than the diameter of the outer shaft, the enlarged head having a cutting edge on its longest side to match the cutting edge on the outer shaft; two nuts at the opposite end from the cutting edges which hold the head of the inner shaft against the end of the outer shaft; a spring which keeps the cutting edges open, and handles or a handle and lever as shown in the drawing to operate the cutting edges or jaws of the cutter.

I do not wish to be understood to limit myself to the particular type of handle shown in the drawing as manifestly a pair of levers similar to pliers or scissors handles would operate the cutting edges. In the drawing a handle and lever are shown.

In the accompanying drawing Figure 1 shows the actual size of the tool and the other figures are twice the actual size.

Fig. 1 is a perspective view of the tool. Fig. 2 is an elevation of part of the tool with part of the handle sectioned. Fig. 3 is a horizontal section of the tool through the plane a b Fig. 2. Fig. l is an elevation of the eccentric shaft. Fig. 5 is a top view of the eccentric shaft. Fig. 6 is an elevation of the inner shaft, and Fig. 7 is a top view of the inner shaft.

Similar letters refer to similar throughout the several views.

The inner shaft A which carries the enlarged head and cutting edge it turns within the outer shaft B, which has a cutting edge 13, so that the cutting edge A and the cutting edge B form a cutter. The base 0 of the outer shaft B fits into the handle E and is fastened with a screw 1. The cutter is operated by means of the lever D which is fastened to the inner shaft A by means of the screw F. The spring G which is fastened to the screw F and to the outer shaft at H is for the purpose of keeping the of the cutter open. N N is a lock nut on the inner shaft A which keeps A E in proper position. X X is the eccentric bore in the shaft B.

The tool is used in the following manner:-It is inserted through the hole in the lamp until the anchor wire comes between the cutting edges. The operator presses the lever with his thumb, or if scissors or pliers handles are used he presses the handles together in the usual way. This causes the inner shaft to turn so that the cutting edges come together cutting the wire at any de sired length. When the pressure is removed from the lever or handles the spring causes the inner shaft to return to its original position, separating the cutting edges. is it is sometimes necessary to lengthen the anchor wire in a manner well known to those employed in the business of repairing incandescent electric lamps, my invention can be used as a pair of pliers or as a pair of pincers in that operation, and I consider as within the scope of my invention the use of said tool not only as a cutter but also as a pair of pliers or pincers.

lVhat I claim and desire to secure by Letters Patent is l. A wire cutting tool with cutting edges on the extremities of two shafts, one of the shafts turning within the other; the outer parts shaft being bored eccentrically from end to end and having a cutting edge on the thick part of its wall; the inner shaft having an enlarged head of not greater diameter than the outer shaft and having a cutting edge on its enlarged head, this cutting edge being so placed in relation to the cutting edge on the outer shaft that the two edges form a cutter of relatively small diameter which is operated by handles, or a handle and lever substantially as described.

2. A. cutting tool having an outer shaft with an eccentric bore, a cutting edge at one end of said shaft, an inner shaft which turns within the outer shaft and has a broadened head on which there is a cutting edge corresponding with the cutting edge on the outer shaft, the two cutting edges making a cutter when the inner shaft is turned within the outer shaft, the tool having handles or levers by which it is operated, one of the handles being attached to the outer and the other handle or lever to the inner shaft, substantially as described.

A tool to be used for cutting or grasping filaments, wires or other parts within the bulbs of incandescent electric lamps, and having a shaft with an eccentric bore containing an inner shaft which turns in the bore, cutting edges or nippers on one end of the shafts, nuts for holding the ends of the shafts carrying the cutting edges or nippers together and with actuating handles or levers substantially as described.

a. A tool for the purpose described having shaft with an eccentric bore, an inner shaft turning in the eccentric bore, cutting edges on one end of th shafts, nuts for holding the ends of the shafts carrying the cutting edges of the tool together, a handle or lever attached to the inner shaft and a handle or lever attached to the outer shaft substantially as described.

ELMER F. DVVYER. 

